The present invention relates generally to a bypass valve of the type used with water softeners, which includes a valve body retaining a spool for alternately connecting feed ports to service ports or connecting adjacent feed ports. More particularly, the present invention relates to a bypass valve and a spool with inlet and outlet passages provided through the radial center of the spool for allowing water to flow through the center of the bypass valve without being obstructed by an impeding center shaft.
Bypass valves are known and used to first connect a water source to a water softener or other water processing device, and second, to connect the water softener to plumbing fixtures for use of the treated water. The known bypass valves have a service side facing the source of untreated water and a valve side facing the water softener. Service ports, located on the service side, include a service inlet connecting the water source to the bypass valve, and a service outlet connecting the bypass valve to the fixture. Similarly, on the valve side, valve ports are known and include a valve outlet carrying untreated water out of the bypass valve and to the water softener, and a valve inlet carrying treated water from the softener to the bypass valve.
In addition, conventional bypass valves also have a bypass passage configured so that water entering the valve through the service inlet can exit the valve through the service outlet, thus skipping treatment by the softener. An example of such a bypass valve is disclosed in U.S. Pat. No. 5,152,321. The use of the bypass valve, which is manually actuated, prolongs the supply of treated softener water when the use of harder water is adequate, such as for watering the lawn or washing a car.
Some known bypass valves use a central shaft that must be moved axially to selectively close and connect pathways. This type of bypass valve, however, requires a complex mechanism to move the shaft and attach the shaft to a body of the bypass valve.
Other conventional bypass valves use a rotating shaft with a number of disks or lands attached to the shaft. The lands and shaft define passages that connect the service ports to valve ports on the opposite side of the central shaft from the service ports. The lands separate the passages on the spool by providing sidewalls for the passages. This configuration, however, necessarily places the shaft in a position that intersects the direct line of flow from the service ports to the valve ports. In other words, the central shaft impedes the flow of water through this type of bypass valve, and in some cases may result in low unusable water pressure at the service outlet.
This conventional configuration is even more detrimental in the type of bypass valve that has the position of an inlet, such as the service inlet, axially offset along a longitudinal or rotational axis of the spool from the exact diametrically opposite position of a corresponding valve outlet on the valve body. In this type of bypass valve, due to the design of the spool and the ports, the valve ports are placed closer together than the service ports. Since these offset flow passages already introduce a pressure drop as a result of the arrangement of the ports, the blockage of direct flow by a central shaft introduces a second loss in pressure.
In addition, bypass valves are also known to have grooves along the outer edge of the lands. O-rings are placed within the grooves to provide a tight seal between the land and the inner surface of the bypass valve body. The typically circular shape of the O-rings tends to limit the land configuration.
Thus, a main object of the present invention is to provide an improved bypass valve that efficiently changes the path of the water without significantly lowering the water pressure.
Another object of the present invention is to provide an improved bypass valve that has a non-circular O-ring that conforms to the shape of a curved land so that the land can be shaped to keep the central portion of the bypass valve open and to prevent impeding the water flow.
A further object of the present invention is to provide an improved bypass valve for disconnecting service ports from valve ports while connecting a bypass passage, which has a simple mechanism for rotating the spool while simultaneously preventing axial movement of the spool.
Yet another object of the present invention is to provide an improved bypass valve that is simple to assemble with a minimum number of components.